<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <div></div>
    <script>
        console.log(location.search); //?uname=andy (获取到参数)
        //1.先去掉?  substr('起始位置',截取几个字符);
        var params = location.search.substr(1); //第二个参数省略表示截取到最后一个字符(uname=andy)
        console.log(params);
        //2.利用=把字符串分割为数组 split('=');
        var arr = params.split('='); //数组 ['uname', 'andy']
        console.log(arr);
        //3.放入div中
        var div = document.querySelector('div');
        div.innerHTML = arr[1] + '欢迎您';
    </script>
</body>

</html>